A conventional example of the exhaust-gas processing device for the diesel engine comprises a DPF, a PM deposited-amount detecting means, a forced-regeneration means, a forced-regeneration control means and a forced-regeneration alarming means (for example, see FIGS. 1 and 2).
According to the above conventional technique, the DPF captures the PM in the exhaust gas. And when the device comes to a first state where the detected value of the PM deposited amount reaches a first set value, while the vehicle is running, a running-forced-regeneration for activating the forced-regeneration means is automatically initiated to burn the PM for removing it. Further, if the device comes to a second state because the PM cannot be burnt for removal by the running-forced-regeneration and therefore the detected value of the PM deposited amount increases as much as it reaches a second set value higher than the first one, the forced-regeneration alarming means is activated to warn it is necessary to perform a stopping-forced-regeneration for recovering the forced-regeneration means when the vehicle stops.
However, this conventional technique cannot warn the necessity of performing the stopping-forced-regeneration unless the detected value of the PM deposited amount reaches the second set value higher than the first one after the detected value of the PM deposited amount has reached the first set value and then the running-forced-regeneration has been initiated. Thus this causes a problem.